Joining device.



PATENTED DEC. 10, 1907. 3.. POHLMANN- JOINING DEVICE.

APPLICATION FILED APR.13.1907.

W/ TNE SSE S A TTOHNEYS HENRY POHLMANN, or NEW YORK, N. Y.

JOINING DE VIOE.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed April 13. 1907- Serial No. 367,943.

To all whom 'itmay concern:

Be it known that I, HENRY POHLMANN, a citizen of the UnitedStates, and a resident of the city of New York, borough of Manhattan, in the county and State of New York, have invented a new and Improved Joining Device, of which the following is a full, clear, and exact description.

The invention relates to wood-working, and its object is to provide a new and improved joining device for securely and firmly olding wooden parts together, such as the wrest plank and back frame of a piano, to provide for the strain exerted on the wrest plank by the strings.

The invention consists of novel features and parts and combinations of the same, which will be more fully described hereinafter and then pointed out in the claims.

A practical embodiment of the invention is represented in the accompanying drawings, forming a part of this specification, in which similar characters of reference indicate corres onding parts in all the views.

igure 1 is a plan view of the improvement as ap lied; Fig. 2 isa sectional side elevation o the same, on the line 22 of Fig. 1, and Fig. 3 is a perspective view of the im rovement.

s illustrated in Fi s. 1 and 2, the wrest vent the wrest plank A from being torn loose by the strain exerted on the wrest plank by the iano strings, a joining device is provide referably made of a single piece of metal, ormed with a loop C, a shank D and a head E. The loop 0 has-its lower edge 0? sharpened, to permit of readily driving the loop down into the top of the back frame B, in the direction of the grain of the wood, the wood being held against splitting by providing the top of the back frame B with trans- 'versely extendin saw cuts B, as plainly shown in Fig. 1, t e saw cuts also permitting an easy driving of the loop 0 down into the wood. The shank D and the head E fit snugly into a recess formed across the to of the wrest plank A, the head E being re erably triangular in shape, the base 0 the triangle forming the outer face of the head, and the said face being flush with the front face of the wrest plank A, as shown in Figs. 1 and 2. The sides of the shank D are provided with vertically extending lugs D having their lower ends D sharpened to readil pass into the wood of the wrest plank when the device is driven into position, it being understood that the grain of the wrest plank runs in a longitudinal direction, that 1s, at right angles to the shank D but in alinement with the lugs D for the latter to readily pass into the wood without danger of splitting the same. The lower portion of t e shank D and its head E extend somewhat below the sharpened bottom edge 0 of the loop C, to provlde a greater depth for the shank D and the head E, thus increasing the holdin capacity of the head E on the wrest Ian A.

As s own in Figs. 1 and 2, the front ortion of the wrest plank A is usually ma e of several layers of wood A glued together, and by the use of the device all the parts which are glued together are securely held in place, and the wrest plank A is capable of readily withstanding the strain exerted by the strings on the string pins attached to the wrest plank A in the usual manner.

In practice, a number of joining devices, as shown and described, are used for each wrest plank, the several devices being spaced suitab e distances apart, but each is flush with the top with the wrest plank A and the back frame B, and the face of the head E is flush with the front face of the wrest plank, so that no undesirable duced.

Although I have shown the loop C of approximately egg-sha e, I do not limit myself'to this form, as t e same may be varied, and also I do not limit myself to the particular shape given to the head E.

As the device is made of a single piece of metal, it can be cheaply manufactured and readily placed in position to securely hold the wooden parts together.

Having thus described my invention, 1

claim as new and desire to secure by Letters Patent:

1. A device for joining woode'n parts comprising a loop for engagement with one of the wooden arts, a shank projecting integrall from tlie loopand engaging the other Woo en part, and a head integrally on the end of the shank for engaging the face of the part engaged by the said shank.

2. A device for joining wooden parts comprising a loop for engagement with one of the wooden parts, a shank projecting inteprojections are proprising a loop havin its lower end beveled,

one of the wooden for engagement wit I integrally from parts, a shank projectin the loop and engaging t e other wooden part, and a head inte rally on the end of the shank for engaging t e face of the part engaged by the said shank.

4. A device for joining wooden parts comprising a loop for engagement w1th one of the wooden arts, a shank projecting integrall from t 1e loop and engaging the other woo en part, and a head inte rally on the end of the shank for engaging t e face of the part engaged by the said shank, the said ead being approximately triangular in shape, the base of the triangle forming the outer face of the head.

5. In combination, the wooden parts to be joined together, and a joining device for the said wooden parts and formed of a single piece of material, having a loop, a shank and a head, of which the loop is driven into one of the wooden parts and the shank and head fitting into corresponding recesses formed in the other wooden part.

6. In combination, the wooden parts to be joined together, and a joining device for the said wooden parts and formed of a single piece of material, having a loo a shank and a head, of which the loop is riven into one of the wooden parts and the shank and head fitting into corresponding recesses formed in the other wooden part, the wooden part receiving the loop being provided with saw cuts to permit ready entrance of the loop.

7. In combination, the wooden parts to be joined together, and a joining device for the said wooden parts and formed of a single piece of material, having a 100 a shank and 'a head, of which the loop is riven into one .of the wooden parts and the shank and head fit into corresponding recesses formed in the other wooden part and across the grain thereof.

8. In combination, the wooden parts to be joined together, and a joining device for the said wooden parts and formed of a single piece of material, having a loo a shank and a head, of which the loop is riven into one of the wooden parts and the shank and head fit into corresponding recesses formed in the other wooden part, the said shank being pro-,

vided at its sides with vertical lugs pointed at the lower ends and adapted to be driven into the wood.

9. A device for joining wooden parts com,-

prising a loop for engagement with one of 4 the wooden arts, a shank projecting integrall from t 1e loop andengaging the other woo en part, and a head inte rally on the end of the shank for engaging t e face of the part engaged by the said shank, the height 7 of the shank and head exceeding that of the loo I 1 h testimony whereof I have signed my name to tlnsspecification in the presence of two subscriblng witnesses.

HENRY POIILMANN.

Witnesses:

RICHARD POIILMANN, ADELAIDE RUCKSTUHL' 

